The present invention relates to a timer mechanism in a clock.
Heretofore, a timer mechanism in a clock has been proposed having at least a manually settable timer drum for manually setting the time at which the timer is to be actuated and having a pair of diametrically oppositely located throughholes, a pair of complementarily arranged semicircular stationary contacts electrically insulated from each other and adapted to actuate the time when they are electrically connected to each other, a resilient contact member rotated in coupled relation to the clock mechanism and having a pair of diametrically oppositely located contact fingers adapted to be moved through the respective throughholes of the timer drum when they are brought in registered relationship with each other during the rotation of the resilient contact member so that the contact fingers contact with the respective semicircular stationary contacts thereby actuating the timer at the set time as set in the timer drum.
In such a timer mechanism, however, the timer drum is normally molded from a plastic material requiring the wall thickness thereof to be substantially great in order to maintain the mechanical strength permitting the throughholes to be formed therein and the timer drum to be accurately manipulated by the operator's hand. Therefore, the movement of the contact fingers of the resilient contact member through the throughholes for effecting the electrical connection to the semicircular stationary contacts must be made great so that substantially great spring force of the contact fingers is required to insure proper actuation of the fingers. Thus, the torque for rotating the resilient contact member having its fingers frictionarily sliding along the wall of the timer drum during the rotation of the resilient contact member must be substantially great thereby resulting in the large consumption of electric power while the variation in load during the actuation of the timer is made great.
The present invention aims at avoiding the above described disadvantages of the heretofore proposed timer mechanism.